VIBRATIONAL-EXCITATION OF PRODUCTS OF DISSOCIATIVE RECOMBINATION

It is shown that a considerable fraction of any molecular product of the dissociative recombination of a polyatomic ion is normally vibrationally excited. The usual main source of the excitation is the impulsive force between the products. In the case of a monohydride, the vibrational excitation due to the impulse acting on its heavy atom is inappreciable, but that due to the much weaker impulse acting on its H atom may be great. Another source is rooted in the relic of the normal vibrational modes of the ion. This causes the initial vibrational wavefunction of the product to differ from the wavefunction of its zeroth vibrational level, even in instances where the corresponding equilibrium separations and force constants of the ion and the product are virtually the same (as they commonly are). If the ion is bent, as for example is OCOH+, an impulsive couple may act on one or more of the products and cause high rotational excitation.